Small Household Appliances/under-counter lights

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QUESTION: We have some under- the- counter lights to replace but having difficulty finding the correct bulbs. According to the printed info on the rim (but not on the bulb itself) the requirement is 120V, 20W.
I have attached a picture of our bulb. You can see that the pins are straight, unlike some that are fattened at the bottom.  I have seen bulbs that look identical at some hardware shops, but they are 12V, not 120V. Here's my question: Since there is nothing printed on my bulb, is it possible that my bulb is actually 12V? I have seen 120V bulbs but they are shaped slightly different, and they won't fit. Is it possible that a 12V bulb will do the trick? Thanks.

ANSWER: I am only guessing, but I think the bulb that you have is 12VAC.  There must be a transformer somewhere in the wiring to drop the voltage from 120 to 12.  If you follow the wires back to where they plug into your house current, you may find a transformer.  If you find such a transformer, there should be an input and output reading on it.  The input will be 120VAC and the output will be what voltage your bulb is.  I think you will find replacement bulbs at a building center if you know the voltage.

Please visit our web site: www.kieferappliance.com  

---------- FOLLOW-UP ----------

QUESTION: What's the difference between 12V and 12VAC? The rest of your instruction regarding following the wires may be correct but I'm no electrician, so there's no way I could follow through on it.

Answer
I will try to be a little clearer.  120VAC is the current that comes out of your wall sockets.  If you touch the hot lead you would get a shocking experience.  After it is changed to 12VAC it would no longer be a shocking experience as the voltage would be too low.  AC is alternating current and DC is direct current.  DC voltage will not shock you even at higher voltage.  I think that the light bar that you have has been transformed to 12VAC which is a much safer current to deal with but sometimes they use a transformer to change 120VAC to 12VDC.  THis does require another system with diodes in it that changes the AC to DC voltage.  A 12VAC bulb will not work in a 12VDC circuit and visa-verse. If you would like to know exactly what you have, you can purchase a Volt-Ohm meter for usually under $20 and measure the exact voltage and if it is AC or DC.  Touch one lead to each side of the bulb socket and it will read the voltage.  Be sure to use the AC or DC scale on the meter to see which it is.  The reason they use low voltage is that it can use much less power and saves energy.  

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Wayne Kiefer

Expertise

Any concerning the repair of small electric household appliances (coffee makers, waffle makers,etc.) shavers, antique clocks, air compressors, lamps, generators.

Experience

High school Industrial Arts teacher. Plant manager at Trek Bicycle factory. Self employed for last 20 years in the small appliance repair business.

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